Beetel 777VR1 Excessive Authentication Vulnerability via UART Interface

A vulnerability exists in the Beetel 777VR1 broadband router, specifically in the UART interface, on firmware versions up to 01.00.09/01.00.09_55. This vulnerability allows unlimited authentication attempts without any form of rate limiting or account lockout, creating a significant risk for brute-force attacks on administrative credentials. The issue arises from the lack of proper authentication attempt restrictions, enabling physical access to the device to be exploited for unauthorized access.

Impact

Exploitation of this vulnerability could lead to unauthorized access to the router's diagnostic shell, allowing an attacker to manipulate device settings or functions. Given the widespread use of the Beetel 777VR1 in India, particularly in residential and small business environments, this vulnerability could affect a large number of users.

Reproduction

The vulnerability can be reproduced by accessing the UART interface of a Beetel 777VR1 router running the affected firmware. Once connected, an unlimited number of authentication attempts can be made without any restrictions, such as delays or account lockouts. This allows for rapid credential guessing or brute-force attacks against admin accounts.

Remediation

It is recommended to implement authentication rate limiting, introduce delays or account lockouts after repeated failed attempts, and log and alert on multiple authentication failures.